harlekin.me

The Rus­si­an mis­si­le that struck the Ukrai­ni­an city of Dnipro on Thurs­day reached a top speed of more than 13,000 kph (8,000 mph) and took about 15 minu­tes to reach its tar­get from its launch, Ukrai­ne said on Fri­day in its first public assess­ment of the new weapon.

src: click (Reu­ters)

So I was inte­res­ted in what height the Medi­um ran­ge mis­si­le nee­ded to reach its tar­get speed.

So one 2 minu­te goog­le search and one rus­si­an mili­ta­ry enthu­si­asts forum later…

src: click

Gran­ted, rus­si­an lea­ning source -- but thats not a para­bo­la. Thats a hyper­bo­la. Max height is at 160km alti­tu­de. Distance tra­v­eled should be around 790km. Lets find a para­bo­la cal­cu­la­tor on goog­le: click

Length Along Axis: 160km
Length of Chord: 790km
=
Arc length = 869km

At Mach 10 which is 3400m per second, … thats 5 minu­tes. Mach 10 was reached in the last seg­ment, so I tried to sol­ve for initi­al velo­ci­ty, whe­re quo­ra was excep­tio­nal­ly hel­pful… 🙂 (click) And once I had my initi­al velo­ci­ty value (3000m per second), I ent­e­red tho­se into an online pro­jec­ti­le moti­on cal­cu­la­tor and sol­ved for time, aaaand…

5 minu­tes.

If you trust a MIT pro­fes­sor in a rus­si­an affi­ni­ty source on initi­al ang­le, and max height reached. 🙂

Initi­al velo­ci­ty would have had to be 950m/s for that rocket­f­light to last 15 minutes.

And if you enter 950 m/s as the initi­al velo­ci­ty speed into this second pro­jec­ti­le for­mu­la cal­cu­la­tor which also takes gra­vi­ty into account, it will tell you, no solu­ti­on, check your para­me­ters. It even does that at 2500 m/s initi­al velocity.

Ups.

Ukrai­ni­an math.

(Or the MIT pro­fes­sor in a rus­si­an affi­ni­ty source lied about ang­le and max height. 🙂 )

edit2: Nope, pro­fes­sor didnt lie. Ukrai­ni­ans are lying bastards.

BBC on North kore­an mis­si­les: click

Mea­ning 500km max alti­tu­de (which would exp­lain a 15 minu­te flight) only nee­ded for 2700km range.

Insti­tu­te for Near East and Gulf Mili­ta­ry Ana­ly­sis on short to medi­um ran­ge missiles:

For a short-to-medium ran­ge mis­si­le that is laun­ched at a tar­get of, say, 650km away, the mis­si­le will reach an alti­tu­de of 130-150km befo­re re-entry.

src: click

Dazu die deutsch­spra­chi­gen Medi­en: “We just print what the Ukrai­ne told Reu­ters. We be gre­at jour­na­lists *blub*.”

edit3: The pro­fes­sor men­ti­ons a dif­fe­rent launch site than wiki, about 2100km away, and also likely a hig­her alti­tu­de, but the cur­ve is still a hyper­bo­la, not a para­bo­la. 2100km away would exp­lain the 15min of tra­vel time though. Alt­hough that would mean that wiki­pe­dia is wrong, which used a NYT report as its source, in regards to the likely launch loca­ti­on named on there.

edit4: Alle­ged launch loca­ti­on 2100km away would have been in Bai­ko­nur, Kasachstan: 

edit5: Look at me, I’m a para­bo­la! Not.

src: click

edit: If you want to have more fun, start thin­king about whe­re (geo­gra­phi­cal­ly) the apex was, whe­re the what, 30 (?) payloads were released. 🙂

Veröffentlicht by me am Sonntag, 24. November 2024 unter Allgemein, Media.